rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 ticks this GP) idle=facc/1/0x4000000000000000 softirq=66535/66535 fqs=0
rcu: 	(detected by 1, t=10502 jiffies, g=92121, q=131 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 16553 Comm: syz.0.3407 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:hlock_class kernel/locking/lockdep.c:223 [inline]
RIP: 0010:__lock_acquire+0x1147/0x7eb0 kernel/locking/lockdep.c:5167
Code: 0f 85 bd 02 00 00 48 83 7c 24 68 00 0f 84 f8 01 00 00 48 8b 84 24 98 00 00 00 48 8d 58 f8 48 89 d8 48 c1 e8 03 42 0f b6 04 00 <84> c0 0f 85 0b 10 00 00 8b 03 89 c3 81 e3 ff 1f 00 00 c1 e8 03 25
RSP: 0018:ffffc900000078e0 EFLAGS: 00000802
RAX: 0000000000000000 RBX: ffff88802afc8ba8 RCX: 00000000fae9315e
RDX: 000000001b5d732a RSI: 00000000001048a1 RDI: ffffffff91fe5500
RBP: ffffc90000007b28 R08: dffffc0000000000 R09: 1ffffffff23fcaa0
R10: dffffc0000000000 R11: fffffbfff23fcaa1 R12: 0000000058cce5e7
R13: ffff88802afc8000 R14: 00000000c8d5ebdc R15: ffff88802afc8bd0
FS:  00007f7e0379f6c0(0000) GS:ffff8880b8c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33323ffc CR3: 000000003ed59000 CR4: 00000000003506f0
DR0: 0000000000010000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5790
 rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 rcu_read_lock include/linux/rcupdate.h:786 [inline]
 advance_sched+0x9f3/0xc70 net/sched/sch_taprio.c:1002
 __run_hrtimer kernel/time/hrtimer.c:1754 [inline]
 __hrtimer_run_queues+0x525/0xc10 kernel/time/hrtimer.c:1818
 hrtimer_interrupt+0x39d/0x980 kernel/time/hrtimer.c:1880
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
 __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:arch_clear_bit_unlock_is_negative_byte arch/x86/include/asm/bitops.h:101 [inline]
RIP: 0010:clear_bit_unlock_is_negative_byte include/asm-generic/bitops/instrumented-lock.h:78 [inline]
RIP: 0010:folio_unlock+0xe3/0x2f0 mm/filemap.c:1553
Code: 11 d1 ff 49 83 e6 01 0f 85 af 00 00 00 0f 1f 44 00 00 e8 b0 0c d1 ff 48 89 df be 08 00 00 00 e8 f3 13 2a 00 31 f6 f0 80 23 fe <40> 0f 98 c5 40 0f 98 c6 bf 02 00 00 00 e8 1b 0f d1 ff 40 84 ed 74
RSP: 0018:ffffc9000ba8f768 EFLAGS: 00000202
RAX: ffffffff81b6c701 RBX: ffffea0001332e00 RCX: ffffffff81b6c73d
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffea0001332e00
RBP: 00fff8000008002d R08: ffffea0001332e07 R09: 1ffffd40002665c0
R10: dffffc0000000000 R11: fffff940002665c1 R12: 1ffffd40002665c1
R13: 1ffffd40002665c0 R14: 0000000000000000 R15: dffffc0000000000
 filemap_map_pages+0xf5c/0x19c0 mm/filemap.c:3663
 do_fault_around mm/memory.c:4595 [inline]
 do_read_fault mm/memory.c:4628 [inline]
 do_fault mm/memory.c:4775 [inline]
 do_pte_missing mm/memory.c:3689 [inline]
 handle_pte_fault mm/memory.c:5047 [inline]
 __handle_mm_fault mm/memory.c:5190 [inline]
 handle_mm_fault+0x3845/0x4a40 mm/memory.c:5355
 faultin_page mm/gup.c:868 [inline]
 __get_user_pages+0x604/0x1580 mm/gup.c:1167
 populate_vma_page_range+0x2c1/0x380 mm/gup.c:1593
 __mm_populate+0x260/0x390 mm/gup.c:1696
 mm_populate include/linux/mm.h:3383 [inline]
 vm_mmap_pgoff+0x2da/0x3f0 mm/util.c:578
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f7e0299f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7e0379f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f7e02c25fa0 RCX: 00007f7e0299f559
RDX: 0000000000000003 RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f7e02a36b20 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7e02c26038 R14: 00007f7e02c25fa0 R15: 00007ffc6f37e1a8
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g92121 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=46582
rcu: rcu_preempt kthread starved for 10502 jiffies! g92121 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:27848 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5393 [inline]
 __schedule+0x15ae/0x4700 kernel/sched/core.c:6722
 schedule+0xbd/0x170 kernel/sched/core.c:6796
 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 16553 Comm: syz.0.3407 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:instrument_atomic_read include/linux/instrumented.h:-1 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3809 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3865 [inline]
RIP: 0010:__lock_acquire+0x1431/0x7eb0 kernel/locking/lockdep.c:5171
Code: 00 04 00 0f 85 96 12 00 00 89 c3 81 e3 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 00 55 fe 91 be 08 00 00 00 e8 9f e9 77 00 <49> b8 00 00 00 00 00 fc ff df 48 0f a3 1d 7d 63 95 10 72 25 48 c7
RSP: 0018:ffffc90000007920 EFLAGS: 00000056
RAX: 0000000000000001 RBX: 000000000000006c RCX: ffffffff8168f171
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff91fe5508
RBP: ffffc90000007b68 R08: ffffffff91fe550f R09: 1ffffffff23fcaa1
R10: dffffc0000000000 R11: fffffbfff23fcaa2 R12: d57e1d102ea6ccdd
R13: ffff88802afc8000 R14: 000000002ea6ccdd R15: ffff88802afc8bd0
FS:  00007f7e0379f6c0(0000) GS:ffff8880b8c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33323ffc CR3: 000000003ed59000 CR4: 00000000003506f0
DR0: 0000000000010000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5790
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
 _raw_spin_lock_irq+0xaf/0xf0 kernel/locking/spinlock.c:170
 __run_hrtimer kernel/time/hrtimer.c:1758 [inline]
 __hrtimer_run_queues+0x5da/0xc10 kernel/time/hrtimer.c:1818
 hrtimer_interrupt+0x39d/0x980 kernel/time/hrtimer.c:1880
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
 __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:arch_clear_bit_unlock_is_negative_byte arch/x86/include/asm/bitops.h:101 [inline]
RIP: 0010:clear_bit_unlock_is_negative_byte include/asm-generic/bitops/instrumented-lock.h:78 [inline]
RIP: 0010:folio_unlock+0xe3/0x2f0 mm/filemap.c:1553
Code: 11 d1 ff 49 83 e6 01 0f 85 af 00 00 00 0f 1f 44 00 00 e8 b0 0c d1 ff 48 89 df be 08 00 00 00 e8 f3 13 2a 00 31 f6 f0 80 23 fe <40> 0f 98 c5 40 0f 98 c6 bf 02 00 00 00 e8 1b 0f d1 ff 40 84 ed 74
RSP: 0018:ffffc9000ba8f768 EFLAGS: 00000202
RAX: ffffffff81b6c701 RBX: ffffea0001332e00 RCX: ffffffff81b6c73d
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffea0001332e00
RBP: 00fff8000008002d R08: ffffea0001332e07 R09: 1ffffd40002665c0
R10: dffffc0000000000 R11: fffff940002665c1 R12: 1ffffd40002665c1
R13: 1ffffd40002665c0 R14: 0000000000000000 R15: dffffc0000000000
 filemap_map_pages+0xf5c/0x19c0 mm/filemap.c:3663
 do_fault_around mm/memory.c:4595 [inline]
 do_read_fault mm/memory.c:4628 [inline]
 do_fault mm/memory.c:4775 [inline]
 do_pte_missing mm/memory.c:3689 [inline]
 handle_pte_fault mm/memory.c:5047 [inline]
 __handle_mm_fault mm/memory.c:5190 [inline]
 handle_mm_fault+0x3845/0x4a40 mm/memory.c:5355
 faultin_page mm/gup.c:868 [inline]
 __get_user_pages+0x604/0x1580 mm/gup.c:1167
 populate_vma_page_range+0x2c1/0x380 mm/gup.c:1593
 __mm_populate+0x260/0x390 mm/gup.c:1696
 mm_populate include/linux/mm.h:3383 [inline]
 vm_mmap_pgoff+0x2da/0x3f0 mm/util.c:578
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f7e0299f559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7e0379f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f7e02c25fa0 RCX: 00007f7e0299f559
RDX: 0000000000000003 RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f7e02a36b20 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7e02c26038 R14: 00007f7e02c25fa0 R15: 00007ffc6f37e1a8
 </TASK>